📚 Documentation
Developer & API Docs: doxygen/html/index.html
✨ What is LARS?
LARS (Light Augmented Reality System) is a cross-platform, open-source framework for experimentation, education, and outreach in collective robotics.
It leverages Extended Reality (XR) to seamlessly merge the physical and virtual worlds, projecting dynamic visual objects, such as gradients, fields, trails, and even robot states, directly into the environment where real robots operate.
LARS enables indirect robot-robot communication (stigmergy), while preserving all real-world constraints. It turns "invisible" collective dynamics into tangible, interactive experiences for researchers, students, and the public.
🛠️ Key Features
- Projection of Virtual, Visual Objects 🔦
- Marker-Free, Cross-platform Detection and Tracking System (based on ARK) 🎯
- Real-Time Performance ⚡
- Standalone System 🖥️
- Scalability to Collective Size 📈
- Indirect Robot-Robot (Stigmergy) 🐜 and Human-Robot Communication
- Direct Communication Possibility 📡
- Ease of Setup and Robustness 🛠️
- Logging for Post-Production 📝
- Cost Effective 💶
- Open Source 🔓
🎯 Why LARS? (Objectives)
- For Research:
- Supporting reliability, reproducibility, and flexibility in collective robotics experiments
- Improving human-robot interaction
- Enriching environments with virtual objects—*without sacrificing realism or robot constraints*
- Supporting reliability, reproducibility, and flexibility in collective robotics experiments
- For Education:
- Making abstract information observable to humans
- Promoting science communication and public engagement by showcasing embodied collective behaviors of robots
- Making abstract information observable to humans
🏹 From ARK to LARS: Advanced Multi-Robot Tracking & Visual Augmentation
LARS features a robust, real-time tracking module based on the ARK (Automatic Robot Kinematics) algorithm, but goes far beyond:
- ⚡ Dramatically improves speed and accuracy, supporting dense populations (100+ robots) at >35 FPS
- 🔎 Robustly handles occlusions, variable lighting, and noisy backgrounds
- 🔵 Generalizes to **any robot that appears approximately circular from above**—including Kilobots, Thymio, e-puck, and others—without the need for tags, markers, or hardware modifications
- 🏷️ Automatically preserves and recovers robot identities even during close interactions or when robots briefly leave the field of view
Beyond tracking:
LARS projects virtual visual objects (gradients, cues, signals) in real time—directly onto the arena and the robots themselves.
This enables:
- Simulation of virtual environments without hardware changes
- Dynamic, spatially precise feedback to individual robots or entire collectives
- Exploration of new paradigms in human-swarm and robot-environment interaction
🏗️ Architecture Overview
LARS is built on the classic Model-View-Controller (MVC) pattern:
- 🧩 Model: World state, physics, and objects
- 🖼️ View: GUI, visualization, and projector output
- 🎮 Controller: Experiment orchestration, tracking, and logic
🧑🔬 Example Scenarios
- 🗳️ Collective Decision-Making: Track and visualize 100+ Kilobots in a noisy, projected environment
- ⏰ Swarm Synchronization: Record robot states and group dynamics in real time
- 🕹️ Interactive Demos: Let visitors steer/interact with swarms and see collective behavior
- 🧑🏫 Educational Labs: Manipulate real experiments to teach robotics, physics, and complexity
(top, left:) GUI snapshot of 42 Kilobots synchronizing on a grid with their internal binary state being detected by the color of their LED in blue or red,
(top, mid-left:) user view of 63 Kilobots making a collective decision on a tiled environment with projected dynamic noise
(top, mid-right:) GUI Snapshot of 109 Kilobots with the trace of their random movement decaying over time
(top, right:) GUI snapshot of two active balls randomly moving in the bounded arena, being tracked by LARS without the need for any markers
(bottom, left:) GUI snapshot of two Thymios with different colors locating the center of the light distribution (projected by LARS). The trace of each robot shows the consistency of the color detection of each robot over time, even after a collision
(bottom, right:) User view of Thymios moving randomly, with their centroid, the projection of their trajectory (light blue trails), their Voronoi tesselation (black lines) and the corresponding network (green lines).
🚦 Quick Start
LARS runs as a Qt application (Qt 5.6+ recommended). Ubuntu is preferred.
See install_dep.md for full dependency details (Qt, CUDA/OpenCV3, etc.).
Install dependencies (see install_dep.md)
Build with Qt Creator (recommended) or use qmake + make
User permission
In order to operate the Kilobot's OHC, the user needs to be part of the dialout group. Therefore, add the user to the group dialout with command
📄 Citation
If you use or adapt LARS in your research or publications, please cite:
- Raoufi, M., Romanczuk, P., & Hamann, H. (2024). LARS: Light Augmented Reality System for Swarm. In Swarm Intelligence: 14th International Conference, ANTS 2024, Konstanz, Germany, October 9–11, 2024, Proceedings (Vol. 14987, p. 246). Springer Nature.
also include ARK:
- Reina A., Cope A.J., Nikolaidis E., Marshall J.A.R., Sabo C. (2017) ARK: Augmented reality for Kilobots. IEEE Robotics and Automation Letters 2, 1755-1761.
🙌 Acknowledgements
LARS is supported by the Science of Intelligence Cluster of Excellence, Berlin.
Developed and maintained by Mohsen Raoufi.
Open-source under the GNU GPL v3.0.
🔗 See Also
- Kilobot Wiki
- API Docs: docs/doxygen/html/index.html
🙌 Contributions welcome! LARS is for scientists, educators, and all who are curious about collective intelligence in robotics.
